Geomagnetic secular variations (inclination) of high-latitude Fjord Cores e Eastern Canadian Arctic
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AbstractPaleomagnetic nieasurcmcnts are reported from 11 piston cores, from the fiords and shelf of castcrn Baffin Island, N.W.T., between latitudes 66 and 72 degrees north. Thc majority of the measurements arc from bioturbated, massive, or laminated mud, with some drop-stones and graded sand beds. Correctcd radiocarbon dates on the acid-insoluble organic matter fraction, supplemented by AMS datcs on in situ bivalves, indicate that all cores cxtcnd into thc early Holocene, and three extend into the latest Plcistoccnc. Sedimentation rates averaged between 0.2 m/ka and 1.4 m/ka. Because of varying sedimentation rato. the depth scales are converted lo 100 or 200 yr/sample timc serics. The results indicate a scrics of geomagnetic secular oscillations with amplitudes in inclination of c. 10 degrees. A stacked record from four piston cores suggests seven major oscillations in inclination. Times when inclinations consistently exceeded 80 &quot; occurred c. 1.400, 4,500, and 8,000 B.P. The most characteristic oscillation occurred c. 1,400 f B.P., when inclinations were nearly vertical. Inclination errors are associated with gravity flows and/or with an increase in sand content, or changes in physical properties. In one core an intcrval of reverse polarity is attributed to a slump.